Printer Controller for Monitoring an Ink Drop Count

1. A printer controller for a pagewidth printer having a printhead configured to print according to print quality information, the printer having a paper transport mechanism for transporting a sheet of paper along a media path through the printer, the controller comprising: a processor having an address, data and control bus, an expander unit and a decoder unit each coupled to the address, data and control bus and configured to decompress a bi-level black layer and a continuous tone (contone) layer of a page to be printed; a replaceable ink cartridge arranged in the media path and having a first integrated circuit (IC) interfaced with the processor, the first IC containing the print quality information; and a second IC interfaced to the processor, wherein the processor is configured to count a number of drops of ink printed by the printhead, to update a remaining drop count of the ink cartridge using the counted drops printed and to write an updated remaining drop count to the second IC each time a page has been printed, the processor configured to control the paper transport mechanism during printing.

2. The printer controller of claim 1 , wherein the paper transport mechanism includes: a sheet feed roller, a paper drive roller and pinch wheels operatively feeding the sheet along the media path; a mechanical media sensor arranged in the media path between the sheet feed roller and paper drive roller; and a capping mechanism configured to cap the printhead when not in use.

3. The printer controller of claim 2 , wherein the paper transport mechanism includes a motor which is configured to drive the paper drive roller and the pinch wheels at a start and an end of the media path when running in a forward direction, and to drive the sheet feed roller when reversed, the sheet feed roller being configured to transport a topmost sheet from a sheet feeder to the paper drive roller.

4. The printer controller of claim 3 , wherein the motor is configured to reverse only when the sheet is detected by the media sensor.

5. The printer controller of claim 2 , wherein the capping mechanism includes a pivoting capping molding with an elastomeric seal and sponge configured so that when the printhead is not in use, the capping molding is held by a spring against a face of the printhead with the elastomeric seal conforming to the face to create an airtight seal around the printhead.